Hi LOTRJ - I think that the second Trim + Join is going to work, just that there are a few non-obvious pieces poking through in a few areas that you also need to pick to keep, or else you'll get holes there.

To find these pieces, before trimming select the 2 solids and run Construct / Curve / Isect.

This will calculate the intersection curves between the 2 parts, and they will be added to the model as just regular curve objects and they will be selected so you can see them.

After those are created, try to zoom around and inspect the intersections (zoom in a starting point and then rotate around and follow it), you'll see a few places where pieces of the solids are poking through - the one piece is not totally "submerged" in the other:

There is one little piece here:








There is a companion to that on the mirror side, and then there is also this one in the front in the bottom:




Also you may want to just hide the solids after you make the intersection curves so that all you see on the screen are the intersection curves by themselves, that makes it a little easier to see little separate bits floating around.

So those are 3 little areas that have tiny fragments that you need to select if using Trim mode = Keep or else they are going to get discarded and have holes there.

I think if those get selected then you'll be set, I'll give that a try in a minute here myself.

One other note - when you do get a joined srf instead of a solid, it can be handy to have this script set up on a keyboard shortcut:

script:var gd = moi.geometryDatabase; gd.deselectAll(); var breps = gd.getObjects().getBreps(); for ( var i = 0; i < breps.length; ++i ) breps.item(i).getNakedEdges().setProperty( 'selected', true );

That will highlight the "naked edges" (edges that are not joined) so you can see where the holes are exactly, that can help to you figure out what is going on. Try to hit Reset after that so you can zoom in on the selected edges, or if there are a bunch of them in different areas you may want to do a Copy and then hide everything and then do Paste to get just those curves showing on the screen to see where they are.

- Michael